


Caught In A Current

by Daxii



Category: Free!
Genre: Caring, Hurt/Comfort, Language Barrier, M/M, Merman!Sousuke, Realistic/evolutionary approach, Sign Language, injured shoulder, merman au
Language: English
Status: Completed
Published: 2015-04-19
Updated: 2015-05-13
Packaged: 2018-03-24 21:05:45
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 6,273
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3784288
Author URL: https://archiveofourown.org/users/Daxii/pseuds/Daxii
Summary: <blockquote class="userstuff">
              <p>Merman AU where Haru finds injured merman Sousuke in a rockpool, and tries his best to get past the huge communication barrier to help get him back on his... uh... fin?</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

  * For [Genki_Dama4](https://archiveofourown.org/users/Genki_Dama4/gifts).



> This is for the lovely Genki for their lovely support, lovely little chats, lovely little EVERYTHING.

Sousuke realises, belatedly, that he’s got himself in quite the predicament. Belatedly because he’s being jostled awake from a feverish sleep, and he feels… he clicks his tongue in his mouth. What is this? _Dry?_

“Oh, good, you’re awake,” he shoots his head towards the garbled noise, where he finds a face, looking rather concerned as it reaches a hand out towards Sousuke’s shoulder. “You’re hurt…”

Sousuke pulls away, shifting sideways on his tail in the small rock pool. He’s _heard_ of these creatures. The things that live on land, the things that are in cahoots with the giant, floating _hunters_ that gobble up huge shawls of fish in one swoop but… there’s no hunters here. Just a lone two-legged land creature.

They share a similar body structure, right down to the hips, but then the creature has two _legs_ , and Sousuke’s pretty sure he’s got some kind of material wrapped over them, because that’s a funny colour for skin, whereas Sousuke has just one thick limb. The shore-person’s skin is like a pale coral colour, where as he is shimmering on the blue side of white.

“Do you not want me to help you? Are you alright?” he figures the thing is trying to communicate.

It’s smaller than him, both in length and bulk, but Sousuke realises he’s at an obvious disadvantage. This is _their_ territory, and he’s completely confined to tiny dip in the land where the water has become trapped. He looks around for the ocean, and he can see it! But… it’s far away, the tidal pull goes far in this area – he knows this, because this is his hunting ground, and it’s left him behind.

The shore-person gets his attention again by waving his hand, and points to their own shoulder, and then at Sousuke’s.

“I can help,” it squeaks something again.

Sousuke ignores it in favour of studying the wound that’s just got his attention… ah, _yes_ , and it all comes flooding back. That fucking fish and that fucking outcrop and just one slipup in his timing, and that wave had got him, throwing him against the jagged face of rock as he tried to grab his meal, and this was… yesterday, wasn’t it? The day before? He’s not sure.

He knows there was blood, a lot of it, and he knows he tried to hide, because everyone knows what blood attracts and – oh yeah.

His own spinning head, hot and sticky, reminds him. He’d gotten sick… probably from leaving the grit in such a deep gash… he must have passed out.

He looks over the rest of his body for injuries. His ribs are bruised and superficially cut, and the delicate skin of his fin is torn, and he thinks there’s probably a break in one of the bones in his tail.

Yep, _quite_ the predicament.

And now he’s only gone and got trapped in the territory of something probably dangerous. Something taking its sweet time finishing him off.

“You can’t understand me, can you?” and there it goes making its weird mouth noises again.

So he makes one of his own.

“Fuck off, just kill me already!” and yells, flailing his arms along with the movement, but _that_ was probably a bit stupid. He winces, going to clutch his shoulder, where he’s taken the brute force of flying into that cliff. Despite the deep, congealed wounds, there’s bone and muscle damage too. It’s pretty fucked.

“Ok, _ow_ , _that’s_ a noise only designed for dolphins to hear…” the thing covers its ears, apparently offended – rightfully – by Sousuke’s outburst. It crouches by him, and points at itself. “Haru,” and it repeats it “Haru.”

Sousuke mimics the noise. Maybe it’s a peace offering. “Haru.”

It takes another step closer. Sousuke is having _none_ of that. He grabs a handful of sand, flinging it at him.

It steps back.

Oh look, they’ve communicated.

“Alright, fine. I get it. Just wait for the tide.”

And wait for the tide he did, thankfully alone. The salty water would sting when it came to lick at his wounds, but he knows from experience it will do them good. He can’t believe he got an infection in the first place.

It takes _hours_ , and it’s hot and he’s dry and good _god_ is he hungry. When the tide finally does reach his little pool, he discovers another unfortunate problem.

He’s stuck.

Well, not _stuck_ , but he can’t heave himself up and out of the small crater in the ground with his tattered shoulder and it’s not filling with enough water to make him float, and his tail just hangs there like a dead weight.

… _Hmm_.

This is an issue.

 

Haruka smirks, from a distance of course, watching the flailing merman from his look out perch on the cliff top. It’s a fascinating creature, honestly, he’s in _awe_ …but… he’s stupider than expected.

Though maybe Haru’s just a bit grumpy because he’s missed a day of swimming to watch this thing.

Maybe he should try helping again… He’s no expert, that’s for certain, but he’s pretty sure the thing… guy?? won’t want to be swimming off when it gets dark, not with all those injuries and the nocturnal predators coming out to play.

That’s if he’s even _capable_ of swimming at the moment. Huh. Yeah, he’ll give this _helping_ another shot. And if all else fails, he’s got someone on speed-dial who has this helping thing down to an art.

He approaches him slowly. He puts on a voice, something he hopes is calm, sort of comforting, _approachable_ – probably how he spoke to Ren and Ran as toddlers, because it’s not like the fish can understand him anyway.

And fish is… probably the wrong word, actually, because it’s more like some marine mammal, like a dolphin. About as graceful as a beached one, too. It’s totally wedged in that little rock pool.

“Hey,” he calls out softly, and the sulking creature doesn’t even break his rhythm of little hops on his tail for some leverage when he sends a handful of sand straight at Haru. “Well, aren’t you just fucking uncalled for,” he mutters, his “nice” voice having lasted only half a second.

The merman hisses at him, like some angry cat, and hurls another handful of beach, this time with rocks in it too. He shields himself with his hand, edging ever closer, inch by inch, crouching down. There’s even more grit and congealed blood in his battered shoulder than earlier, and he can’t help his little wince.

“Let me help,” he tries, gently, and offers out his hand, like he sort of wants the merman to sniff his fingers like a stray dog.

 

Sousuke hisses again. This moron just isn’t getting the hint. It’s the same one from earlier, too. It’s probably been watching him from his den, or whatever it lives in, waiting for him to pass out or dry out and come and peel him and take him back to his pod to eat him. He might not even wait till he’s dead. He shudders. His shoulder twitches. It’s _bad_.

He wonders what will happen if he just gives in and lets himself become supper. He’s kinda giving up on getting out of this ditch like… ever. At least it might be quicker and a little less torturous than starving to death and having the idiot peck at him while he’s all scrawny and rotting. He pauses, looking up at the face so similar to his own, blinks. Once. Twice. And then slumps forwards.

 

Haru rushes forwards to the unconscious merman, pushing him back to lean against the little bank of sand. It’s probably the best option he could have hoped for, having been totally unable to get in to help him while he was awake. He’s glad he’s brought the little medi-pack with him in his day kit. There’s not much, but there’s a few alcohol swabs so he can at least clean up that gash in his shoulder.

The merman flinches, a big, webbed hand coming up and grabbing at his waist, claw-like nails digging in.

“Were you faking?” he asks, amused, nudging his chin up lightly to look at him, and goes back to cleaning.

His eyes are so worried, the most genuine expression of fear, fear for his _life_ he’s ever seen. At that’s when he realises how _vulnerable_ he must feel. He’s broken and trapped and literally a fish out of water. Haru shrinks back. Backing off. Giving him space. He feels the relieved release of breath from the other side of the rock pool.

He holds his hand out again, and the merman shifts back, like he’s going to throw sand again, but instead just looks to the side, like he’s giving up completely. He comes forward again, tending again to his shoulder, and mumbles something quietly, just mindlessly chattering in a way he always finds soothing when Makoto does it, so he hope he’s having the same kind of effect.

 

The moron’s making some kind of chatter, like white noise or thrashing waves, just incessantly, it must be some kind of hunters call, and holy mackerel what is it _doing_ to his _shoulder_. Savaging it off with some kind of poison. Probably dissolving the skin and melting through the bone or something. There’s a smell to it too, harsh on his sensitive nose. He’s a bit frozen, half from fear and half from just… curiosity. This isn’t the way his species hunts at all. He lets himself turn to look.

And his shoulder is _clean_.

“What are you doing?” he asks, quietly, and the two-legged gives him a look. So he’s definitely heard him, but there’s no understanding. He tries a different approach. “Sousuke,” he says.

 

Haru looks at him, the clicking buzz is sort of verbal, like it has sounds he can probably spell out. He repeats it. “Sousuke.”

“Sousuke.”

And then he points at himself, hoping to god that’s the merman’s name and not some expletive, “Haru,” the merman’s already proved he can mimic this noise.

He feels like they’ve come to an agreement, established some sort of base to work from. The shoulder clean – still clearly _mangled_ and probably three degrees from gangrenous and in need of some antibiotics pumping into it – but the merman looks a little relaxed. He backs up a foot, and touches down his ribs, and he – Sousuke – whimpers and flinches, but not like anything’s broken. He wipes over these little cuts too, keeping a careful eye on him. He’s wary and scared, but accepting. Not throwing sand and screeching, at least.


	2. Chapter 2

Sousuke, whether it’s his name or not, gives Haru a cold look when he reaches into his pack, forcing him to ease a hand out gently, palm up for him to see, like he’s surrendering. Slowly, he takes out his water bottle and shows that too, and when Sousuke finally rests his eyes on Haru’s face again, Haru takes that as his cue to approach and open it up.

“You must be thirsty,” he keeps his voice low and quiet, slips into the ditch next to him, even though it’s a tight squeeze. “It’s just water.”

He brings his hand towards one of Sousuke’s, but his fingers are webbed, and on tentatively taking hold of it, running his fingers lightly over and over, sort of tickling, finds it to be damp, like he’s constantly sweating through his palms, but put it down to the whole “merman” thing, but gives up on the idea of him giving himself the drink. He won’t be able to hold the bottle steady, at least not with how he’s slightly trembling, probably with exhaustion.

He tilts his own head back, and then, keeping his hand in view at all times, brings it up to the back of Sousuke’s neck, brushing his fingers over in warning and then resting his palm on. He moves it back, and Sousuke tilts his head obediently, eyes hard on him in what looks like wonder. He pours some water into his mouth, and Sousuke’s eyes become delighted, and he tries to hold the bottle himself, but Haru keeps a hand on to steady it.

“There, feeling better?” he asks, uselessly, twirling one finger into the scruffy hair at the back of Sousuke’s neck. It’s sort of oily, but still marvellously soft. “I bet it tastes weird to you, not being salty…”

He looks him over again. He’s naked, obviously, but he’s not like a cartoon, there’s no shimmering tail made of up fish scales, it’s just… a tail. Just his skin, carrying on, like his legs are simply fused together. His anatomy is different, having little slits where his torso melts into his hips, like the kind you’d find on a dolphin or another sea-mammal. There’s an injury to his tail, though, and he seriously doubts he’ll be able to swim properly with it.

But it’s not like he can leave him here.

 

Sousuke tries to twitch his tail, and _yup_ , definitely broken _something_ in that. The Haru is still twiddling with the back of his hair, even though he’s emptied the container of weird water and put it back in that thing he was carrying. It’s nice, soothing, making him want to go to sleep, but he _can’t_. He just has to get _home_. He flicks his tail again in frustration, and lets out a screeching, yelping string of curses.

“Hey, hey!” the Haru is also yelling, so he looks at it… him? Sousuke can’t really tell, and it sets its hands on his tail, feeling over it VERY uncomfortably, but Sousuke doesn’t shove it off _just_ yet. “Well, aren’t you screwed?”

It scrunches its face up, like it’s _annoyed_ with his tail or something, so he shoves it, making it plop onto its butt in the sand, and it scowls.

“At least your _other_ arm is fine then,” it grumbles unintelligibly, probably pissed off with how ungracefully it’s landed, probably doesn’t like being pushed over to begin with, actually.

Serves it fucking right.

 

Haru sits on the edge of the pool and reaches back into his bag, this time for his phone. He ignores Sousuke, even as he shuffles round to sit by his head again and thread his fingers back through his hair, because he’d seemed to enjoy that, at least a little bit.

“Hey,” Makoto answers his phone, and Haru can hear him smiling, and doesn’t even bother to pull his own face straight again. “You alright, Haru-chan?” because Haru hardly _ever_ calls, so Makoto’s doing a pretty good job of not acting frantically concerned.

“I’m fine,” he assures, and hears the sigh of relief, “I’ve… made a new friend, actually, and… erm… could we get a ride home from the beach?”

Makoto laughs on the other end of the line now. “No problem. Let me guess, I’ll meet you at the rock pools?”

“Yeah,” Haru smiles.

He’s not really sure what their action plan should be. He keeps twirling Sousuke’s hair around his finger, and then pushes his hand up through the spikey mane a few times, and then just pets him… he feels a bit mean, like he’s sort of _animalising_ what is basically just a human with a tail, but _he_ likes having his hair stroked, and Sousuke isn’t arguing, so he’s just winging it here. Makoto will know what to do.

……

Or Makoto might scream when he comes around the side of the cliff and notices the lack of bi-pedal limbs on Haru’s new “friend”.

“NANASE HARUKA!” he bellows. Haru and Sousuke blink towards him, Sousuke tensing at his side, probably terriefied of the newcomer, but the slimy grip that clenches Haru’s ankle feels _strong_ more than anything else… and a bit weird, when he thinks about it, and brushes his fingers off lightly so he can stand up and do something about Makoto.

“Yes?” he asks, lamely, and Makoto splutters, doing a double take, confirms his earlier observation, and opens his mouth to yell something else.

All that happens is a whispered “That’s a mermaid.”

“Merman, actually. Sousuke,” he rakes his fingers through his hair again, and then drops the sarcasm. “He’s hurt.”

“He’s a _merman_ ,” Makoto gasps, still reeling a bit, and scampers closer.

“Don’t _scare_ him,” Haru hisses, holding up a hand to stop his charging friend. “I think he’s got a broken bone in his tail… the structure feels like ribs, so it needs taping… and his shoulder,” Haru winces, looking at the mess where it’s starting to scab again. “Pretty roughed up…”

Makoto collapses to his knees. “He’s a _merman_ ,” he breathes again.

“Yes,” Haru grunts, getting a little bit annoyed. He sits by Sousuke again, stroking his hair on some kind of auto-pilot now. “He probably has another word for it in his language though…”

“He can talk?!” Makoto gapes even more.

Haru shrugs. “Not really. Sounds like a dolphin on whatever the opposite of helium is… he’s being good. Burns your ears. I think he was swearing hell at me when I found him,” and he shoots a look at Sousuke, who looks just as irritated as Haru feels.

“A merman…”

“ _Yes,_ Makoto.”

 

The second Haru is much larger, more Sousuke’s own size, babbling the same sound like it hurts him, with the most complex mix of expressions Sousuke’s ever seen.

“Ha…Haru,” the big one’s saying the word, so maybe it _is_ the little one’s name? “You know this is impossible…”

The little one, his Haru, lifts his shoulders and drops them dismissively. “No it’s not.”

“Mermen _don’t exist,_ Haru.”

“They do,” and his Haru strokes his hair again, and he’s really relaxing into it. It feels so caring, even though it’s so dangerous. But it’s not like he has much to lose. “I’ve always known they do.”

His voice is so soft, and even though it’s just jibberish, Sousuke looks up at him and smiles, and he’s met with eyes as big as the moon and clear and blue as the brightest ocean.

The other one exhales, loudly. “So I suppose we should get him home, then… get these wounds fixed…”

 

Haru knew he’d come around.

Makoto leaves to go and bring the car as close to the little footpath Haru’s worn to this neglected side of the beach as possible. Haru crouches back into the pool, facing his merman, and neatens up his hair with gently combing fingers, and then draws them down his face, neck, collar, in fascination, and stops at his mangled shoulder.

It’s really going to take some work.

“Makoto,” Haru points towards his retreating friend’s back, looking at Sousuke. He points to himself, “Haru,” and then to the merman, “Sousuke,” and just hopes there’s some kind of recognition.

He’s definitely intelligent, Haru just figures they won’t have the same voice box structure. He sounds more like he’s built to communicate with whales and dolphins, and of course his own species, and the clicky squeaks probably serve some kind of echo-location purpose too.

He presents both his hands in front of Sousuke, and makes one walk with two fingers across the palm of the other. “Human,” and points to himself, to where Makoto’s gone.

Sousuke pauses for a moment, but he works it out. He _understands_ what Haru is trying to imply, and Haru can’t quite get over that. Sousuke mirrors the movement, his webbed fingers making it a little more difficult. “Oom,” he clicks.

Haru chuckles softly. “Near enough,” and strokes back one last piece of hair behind his ear.

 

 

**Notes for the Chapter:**

> Is the set up of having Sousuke hear the conversation even though he doesn't understand what Mako and Haru are saying working for people? I want to show his POV, but also don't wanna leave out the dialogue between the ooms :/


	3. Chapter 3

It involves a lot of squealing and squeaking on the part of one big bloke, and a whole lot of concerned frowning on the part of the other. Yeah. Makoto’s the one squeaking. Sousuke is just _confused_. Finally, there’s a quasi-mythical creature laying propped up with Haru’s pillows against his bedroom wall, and Haru crouches close to feed him water through a sports bottle, slowly tipping it into his mouth.

He hears Makoto sigh, hovering in the doorway, and finally turns to look at him, having spent the last ten minutes thoroughly ignoring him whilst getting Sousuke comfortable and calmed down a bit, finally seeing his wide eyes relax into something akin to acceptance. The car, the street, the house, this _room_ … it all must be so alien to him. He’s probably hit a point of just being exhausted with trying to comprehend everything, and that teamed with how much pain it must have caused for him to be manhandled and moved… well… Haru’s pretty proud of him for not biting anyone, that’s for sure.

His hand twirls into his merman’s hair while Makoto speaks.

“Would he not be better off in the bath?” Makoto wonders, having also reached a point of _just dealing with it_.

Haru shakes his head. “I think he’s sort of like a seal? I think he should be fine out of water… especially drinking. He’s more mammal than fish… no gills or anything. Probably best to give him a few hours soaking in the evening or something.”

“What about _you?_ ”

Haru stops petting for a moment, confused. “What do you mean?”

“How are you holding up… you’re very calm…”

Haru just shrugs and brings his attention back to Sousuke, who’s fixed a hard, but almost enchanted stare on him.

“And where’s he going to sleep? Where are _you_ going to sleep?!” Makoto’ gone off on one now, back into his worrying mode, _mothering_ , getting energy from god knows where.

Haru just wants to collapse.

 

So does Sousuke.

He leans back against the soft… thing… sort of like a very straight edged sea-sponge, but different. There’s one behind his head, too, cradling and cushioning. It’s weird, but it’s warm and it’s _nice_ , and he realises just how easily he could go to sleep…

And snaps back to attention.

Because what a _stupid_ idea that would be.

His little oom is on him immediately. Brushing his hair back and cooing something in this soft little voice that doesn’t suit his face or his attitude. Sousuke can just _smell_ the nonchalant all over him, and it annoys him a little, despite all the effort Haru’s going to to do… _whatever_ it is he intends.

“Hey, it’s alright, don’t fight it… go to sleep,” Haru continues to hum, a very quiet little noise that the big one probably can’t hear.

He relaxes. His intentions don’t _seem_ dangerous. At least not yet. But then, he’d be nothing but scraps sinking to the bottom if he’d been in the ocean. He’s as good as dead anyway. The ooms can do what they want with him.

Haru relaxes alongside him, flopping down where the base of his tail should be, so close that Sousuke can feel his body heat, and now he just wants to sleep _more_.It’s just like huddling up with his pod members at night, their combined bulk warding off predators, someone always on guard just in case…

He wonders how his little friends are, Ai and Momo. At that age where they’re just barely branching away from the pod during the day to hunt solo and find mates. They stick close by Sousuke at night. Just because he’s _big_ , he supposes. Hopefully they hadn’t set out to find him… into all that bloodied water.

He shudders, halting his own thoughts from straying further.

Suddenly, there’s a head on his shoulder.

Haru’s head.

He glares at it as the little oom relaxes against him, like he’s just like one of the boys settling close to take a break or nap, using him as a shield for safety. The Makoto-oom is sporting this soft, silly smile over there, and sighs towards them.

“I suppose a nap is for the best, hmm, Haru-chan?” this one has such a soft voice _anyway_ , and now he thinks it must be fussing or cooing at his Haru. He heard the name, anyway. “Can I get you anything?”

Haru holds his arm out, palm gesturing towards the big platform looking thing in the middle of the room, taking up most of the space. Makoto pulls something from it, big and sort of floaty, and comes over cover them with it, taking a _noticeable_ amount of time and care to carefully tuck it around Haru, who looks a strange mix of bored and appreciative. He slows when he gets to Sousuke. It covers his tail and up to his waist, but he’s not brought it up to his chin like he has with Haru.

Haru sorts that out as soon as he’s left the room.

 

Haru manages a good nap. Not long, just enough to get himself functional again. He’s hungry, and he just knows Sousuke must be _starving_ by this point. The merman is awake, looking down at him with an expression he can’t place, but he looks rested at least, whether he’s slept or not.

“I’ll get us some dinner, alright?” he tells him, even though it’s late – dark outside, at any rate – it’s not like it really matters.

He hopes he likes mackerel.

Peeling himself away from the damp (he must just stay really well moisturized?) body, Haru gives him a soft smile, tries to act gentle and unthreatening. He doesn’t want Sousuke to feel abandoned in his bedroom. With a few gentle strokes of his hair, he moves away to the door. But then he has another idea.

Using two fingers, he points them into his own mouth. “Food,” he says to Sousuke.

Sousuke blinks at him, and then, after a moment, looks down and points to his stomach. He gets it. Haru nods, grinning like he hasn’t done in _years_ , and rushes off to the kitchen. He doesn’t fillet or cook the two fat fish he takes out of the fridge for Sousuke, but he does add some salt and water to the bowl, make it a bit more like the ocean. He might want to drink it. The species probably requires a higher salt intake than humans would.

His merman isn’t as happy as he left him when he gets back to his room.

He’s flopped to his side, looks a bit stuck, but his face is just _horrified_ , and Haru goes into panic mode, dumping their dishes on the bed, sloshing water and rice over the sides, but never mind, and scrambles to his side, easing his hands under his ribs to hoist him back into a sitting position, all the while trying to hum anything that might sound vaguely calming.

“Come on, come on,” he brings a hand to his hair again, combing the little tuft at the back of his neck.  “Food.”

He points to his mouth again, and then at Sousuke’s mouth. “Food.”

 

Oh. Ok.

So it’s _mackerel_ on the menu. Sousuke’s _not_ about to be disembowelled and served with a side of seaweed.

Haru brings the fish over in its holder thing, and Sousuke gets a grip on the tail. This is for him?

Haru nods his head, a thing he’s learned means his human _approves_. He takes a bite.

“Food.”

So this is the Haru word for fish? For a meal?

“Foo–” he can’t make that last sound, but Haru is beaming at him anyway.

“You try.”


	4. Chapter 4

Rin… uh.

 _Uh_.

For some reason, Haru had expected Rin to react a little better. Probably _around_ the same level as Makoto, maybe more swearing, almost _definitely_ more excited.

This… this is not what he expected.

The bathroom door slams just as quickly as it opened, and Haru can hear the footsteps pounding as Rin rushes away.

“ ** _MAKOTO!!_** ” Rin bellows, having apparently found their third house mate in what sounds like the kitchen, judging from the echoes Haru can hear rattling through their little house.

Haru doesn’t hear the response, but Rin’s probably interrupted anything he was going to say anyway.

“Why didn’t you _tell_ me our freaky fish boy has a _friend_ with him?!”

“Ah… well it’s a bit of a… long story,” Makoto struggles for his words.

“More like a _short_ story! I’ve never even _met_ this guy and now he’s _with Haru!_ ”

There’s a pause, and Haru glances across the tub at Sousuke. He’s got his legs spread around Sousuke’s tail as best he can, fin sitting in his lap like a warm comfort blanket, and he’s caught himself idly stroking it more than once while they’ve been silently relaxing. Sousuke’s just delighted with the warm water, and don’t even get started on his reaction to _bubbles_.

Haru braces himself. Anyone else might read the situation at face value and give them privacy whatever their opinion on it is. But Rin is…

Well…

He’s _Rin_.

Which is why Haru can only roll his eyes into oblivion when Rin comes tearing back in.

“Good day at work?” he asks with a deadpan, and Rin’s mouth just falls open for a moment as all intelligence abandons him.

 

This new oom is… weird, Sousuke decides, as it looks him up and down with disdain. The side of it… his? mouth cracks open, revealing glinting, predatory teeth. Sousuke instinctively wraps his hand around his Haru’s split fin thing and the bottom of his split tail thing (and hopes to Neptune Haru teaches him a word for these things soon) protectively.

This new oom is _territorial_.

Like Haru is his mate, like this room is his home, Sousuke can’t really tell with these things, but either way Haru looks about 4000% done with his behaviour, sighing and sinking down a little in the water.

“Can’t you see we’re having a bath?” Haru’s speaking to it.

“Just wondering who your friend is… wondering if I might need to evict him… or arrest him,” and the other one is so obviously _growling_ that Sousuke tightens his grip, and shows his own teeth.

“This is Sousuke,” Haru is so calm, and strokes his tail nicely, all tingly and ticklish, _definitely_ not fearful of this new one, and Sousuke relaxes a little. “Rin,” Haru points, and it must be the new one’s name.

They’re staring hard at each other, a thickness in the air Sousuke both isn’t _used to_ , just because it’s fucking _air_ , and also can’t understand. But then Rin glances at him again, less critically, and something softens.

“What happened to your shoulder, pal? You should probably get that seen to… it’ll need stitching at the very _least_.”

Sousuke blinks.

“Can you do stitches?” Haru says, there’s a little lilt in his voice, like when a little kid is gearing up to ask for something, trying to endear their preferred adult.

Rin nods his head slowly, eyes narrowed, and it makes Sousuke want to stroke Haru’s broken fin thing. Just reminding him that he’s _there_ , and even if he’s a bit battered, he’s still the biggest out of all of them.

“Don’t… be… weird,” Haru speaks so slowly, a concerned warning tone.

And then lifts Sousuke’s tail out of the water.

 

Rin reacts just _slightly_ better than he did when he initially thought Haru must have been copping off with this guy in the bath, which is an achievement really, considering it’s _Rin_. At least he doesn’t slam the door and storm off to Makoto this time. He just shouts for him right where he is, and they immediately hear his steps thudding towards them.

“Ah…” Makoto starts, and puts a hand on Rin’s shoulder. “I _told_ you it was a long story…”

“That’s a mermaid.”

“Mer _man_ , really…” Makoto whispers, Rin turning his head away from Sousuke’s tail at last to glare at him for being so pedantic.

“Well have you checked?” Rin grunts. Rin would.

“Oh please,” Haru rolls his eyes. “Just because _you’d_ try and get off with someone on the first day doesn’t mean _I_ would.”

Makoto clamps his hand over whatever Rin is about to spit back. “Guys… I think it’s in everyone’s best interests if we just help him out and get him home…”

“And then _never_ speak of this again,” Rin adds.

Haru nods, looking back to Sousuke who is so _intensely_ stroking his ankles. He can’t have understood a word. There’ll just be all this foreign yelling so obviously _about him_ , and Haru’s so sorry, so so sorry it can’t be easier.

It takes a little coaxing and a lot of reassurance, but Rin and Makoto carry Sousuke between them back to Haru’s room, holding him up for a minute while Haru rubs him down and then covers his bed with towels, a double layer where they’re about to put Sousuke. Rin disappears to his patrol car to collect his first aid box.

Haru scoots close to his merman, cross-legged and pressed into his side, keeping a close eye on his face as he starts to run his hands down his abdomen, feeling for any kind of injury over his ribs and then more importantly any swelling or tenderness over his organs that might indicate internal injury. The only reaction is a concerned little tremble.

“You can’t understand me…” Haru whispers, glancing over his shoulder at the others, but they’ve politely turned away, “but we’re going to try and fix you. But it might hurt,” he reaches out to hover his hand over Sousuke’s torn shoulder, his eyes following it warily, but doesn’t recoil when Haru runs his fingers down his bicep.

They start with taping the broken bones in his tail. Using what they’ve seen in medical dramas and Rin and Makoto’s very vague medical training for their jobs probably isn’t all that wise, but it’s the best they can do. Haru’s pretty much useless here, but does his best to otherwise occupy Sousuke, who’s trying so hard to keep his mouth closed on his native squeaks and clicks. Haru plays with his hands in front of their faces, comparing Sousuke’s pale colouring and webbed, sort of pleasantly slimy fingers and palms with his.

“Right… so that shoulder,” Rin declares, staring distractedly at Sousuke’s tail. “And can we cover him up? I don’t know _what_ you’re doing but he’s _definitely_ a male.”

Makoto grabs the blanket with a blush, covering Sousuke up to his waist, and Haru slides down under it beside him, propped up on one elbow with his arm over his waist.

 

Sousuke fits his arm around Haru, kneading and squeezing nervously.

“You’re cuddling him now? Don’t make it weird. You’re already sharing a bed with a fish,” the Rin one grunts, reaching to flick Haru in the forehead.

Haru doesn’t react, so Sousuke chooses not to snap at him.

“He’s scared… and you’re about to sew him up… I can’t translate that with little dancing fingers, you know,” Haru’s voice is soft again, but there’s such an _edge_. Sousuke figures that the two of them must have equal standing in their pod hierarchy, but both seem to instinctively follow Makoto as the leader, and he doesn’t think it’s just because he’s the biggest.

“Right,” Rin grunts. “Well… distract him, then. If he bites me your both dead.”

 

Haru wishes there was a universal gesture for _sorry_. Sousuke doesn’t _bite_ Rin, but he whips his arm out and hisses such a guttural wail that all three of them are covering their ears.

“Sousuke… Sousuke…” Haru tries his best, getting up close to his face so Sousuke can hopefully _see_ something on his face and calm down.

His moans peters off into whimpers after a moment, and Haru takes him into a hug.

“Just do it quick,” Haru mumbles, bringing a hand into Sousuke’s hair, stroking and twirling.

Sousuke squeezes _hard_ around him, so much Haru lets out a little choked gasp of pain, and knows it’s Makoto’s hand sliding between his ribs and Sousuke’s arm to let the pressure off while Rin stitches. At least Sousuke is keeping still while he has him in such a grip. Haru knows he’s going to bruise, but it doesn’t really matter. It’s nothing in comparison.

“How do you say “you can let go now” in merman?” Rin asks, quietly, stroking at Sousuke’s arm when he’s finished. “Hey. Sousuke, you’re crushing your buddy a bit there.”

Haru feels Sousuke’s head whip towards him, feels a rumbling snarl in his throat, and squeezes a little bit as he starts to pull back.

“So what do we do now?” Makoto asks, coming around and perching next to Haru.

Haru can only shrug. “Let him sleep, I guess…”

 

Sousuke looks at his arm as Haru wriggles away. The wound is… closed… but Sousuke’s not sure if it was worth it. Sharp, like a jellyfish sting, driving into him repeatedly. Rin looks apologetic, and Haru had held him so tightly. He relaxes into the soft thing he’s lying on, trying to scoot down so he’s flat on his back.

It’s submissive, but these guys use words so much he’s not sure how the body language will come across, and all he wants to do is rest. Haru stays beside him. So close. So _protective_ , in its rawest form. This is apparently sleeping quarters, as Haru’s casually closing his eyes as the other two leave with whispered things he doesn’t pay attention to.

It’s so oddly trusting. Where he’s from, this is the most vulnerable time. When any predator can come for you, your pod can betray you. It’s all survival. It’s just how it works. But Haru’s so _comfortable_ , and he’s not stupid. He must feel secure he’s in no danger from Sousuke or the others. The others, he can understand. They obviously have a pod together. But he doesn’t _know_ Sousuke. They can’t even communicate properly.

It’s just instinct.

**Notes for the Chapter:**

> I have more plans for this universe, but I'm posting it as complete because it requires a LOT of work I just don't have the time for at the moment, so subscribe if you're interested in the base I've tried to set up, and we'll see where it goes.   
> This is the hardest thing I've ever had to write. I commend ANYONE who can really stick with doing a detailed merAU, because this is a level of detail I don't often play around with.   
> Thank you for any love or feedback <3   
> And genki, I hope you enjoyed what I've managed. I promise to work more on this in the future. I just wasn't expecting such a CHALLENGE when I started it in the first place, so I'm sorry it doesn't tick all your boxes yet.

**Author's Note:**

> I'm sorry this is so belated, hun!  
> I'm trying to avoid all the samey cliches... I know I've got the ultimate "finding the injured merman on the beach" cliche, but whatever, we're rolling with it.  
> Sou's appearance is kinda based on those mermaids from the "the body found" spoof doc, where they're kinda more "realistic", like they've evolved. So don't expect a sparkly whaleshark tail or anything.


End file.
